Biology of the Cyclostomes

  title={Biology of the Cyclostomes},
  author={M. W. Hardisty},
Distribution, variety and life cycles.- Perspectives and relationships.- Ecology and behaviour.- Respiration and feeding.- The heart and circulatory system.- The skeleton and the muscular system.- The nervous system.- Osmotic and ionic regulation.- The pituitary.- The peripheral endocrine tissues.- Reproduction and development.- Comparative biochemistry, immunology and cytogenetics.- Conclusions and evolutionary perspectives. 

Osmotic and Ionic Regulation in Cyclostomes

Lampreys and hagfish were traditionally grouped together as cyclostomes (“round mouths”) in spite of the many differences in their anatomy, physiology and biochemistry (Hardisty, 1979), but


The coordinate regulation of development-associated changes in lipid metabolism results from interactions among hormones and other internal and environmental cues, which is essential for ensuring availability of lipid during times of need.

Relationship Between Cardiac Energy Metabolism and Cardiac Work Demand in Fishes

The diversity in both anatomy and physiology of piscine hearts raises a wealth of experimental questions for investigators interested in evolution of cardiac function within the vertebrate subphylum.

Respiration in Phyletically Ancient Fishes

This work has interpreted ‘primitive’ rather broadly in order to convey the tremendous diversity of early evolutionary trends in gas exchange mechanisms exhibited by fishes.

The respiratory physiology of anadromous vertebrates: A comparison of blood gas transport in lampreys and salmonids

  • B. Tufts
  • Biology, Environmental Science
  • 1994
The characteristics of blood gas transport in both salmonids and lampreys are described and a comparison of each is made to compare the respiratory strategy of each.

Morphological changes in the liver of the sea lamprey, Petromyzon marinus L., during metamorphosis. II. Canalicular degeneration and transformation of hepatocytes

Degeneration of all bile canaliculi takes place in the liver of the sea lamprey, Petromyzon marinus, during metamorphosis, followed by complete loss of the exocrine biliary pole of hepatocytes and a reorganization of these cells into solid cords.

Cardiovascular Systems in Primitive Fishes

Theory on the evolutionary history of lamprey metamorphosis: role of reproductive and thyroid axes.

  • J. YousonS. Sower
  • Biology
    Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology
  • 2001

Brain and Pituitary Hormones of Lampreys, Recent Findings and their Evolutionary Significance

The most recent information on the structure and function of newly identified hormones and genes of the brain and pituitary in lampreys provides further information for the prediction of gene duplication during the early development of vertebrates and increases the understanding of the molecular evolution and functional diversity of these hormones.